View Full Version : Intermittent problem with SCSI CD-ROM access

2nd February 2015, 13:59
I'm having some problems with my CD-ROM drive connected to my A1200.

Sometimes it will take more than one attempt to open a file, for example I could try running a script file and get an "Unable to open X" requester, then try again and it work OK.
Also if I boot up the machine with a CD already in the drive, when I get to Workbench I get a CD0:???? icon. Issuing a diskchange or physically opening/closing the tray will make it recognise the CD.

It's an external CD writer connected to my Blizzard SCSI interface.

Running KS3.1 and CWB Lite 3.1. I'm using the version of AmiCDFS from the Blizzard SCSI install floppy.

I'm guessing a setting needs to be changed in the CD0 mountfile but I have no idea where to start.

Any ideas?

2nd February 2015, 16:57
Just a couple of general thoughts:

- Have you terminated the SCSI bus at the drive end?
- Is the disk spinning up ok every time you boot so that the OS can read the disk?
- Are the disks damaged in any way? i.e. scratches which might give intermittent read errors?
- Do you have the most up to date scsi.device?
- Not sure about this but, does the SCSI interface on blizzards use PIO and if so is it set low enough or is it DMA access?

2nd February 2015, 17:14
-The drive is supposed to have autosensing internal termination. I do have a passive terminator that I could try. It is currently the only device connected to the controller.
-Yes it spins up fine
-I tried 3 CDs, all exhibit the same problem.
-The version of 1230scsi.device is V8.2
-IIRC it's PIO

3rd February 2015, 09:45
After some further investigation it appears to be a buffer issue.